DBMS UNIT 2 OVERVIEW OF DBMS Database is a collection of related data and data is a collection of facts and figures that can be processed to produce information. Mostly data represents recordable facts. Data aids in producing information, which is based on facts. For example, if we have data about marks obtained by all students, we can then conclude about toppers and average marks. A database management system stores data in such a way that it becomes easier to retrieve, manipulate, and produce information. Characteristics Traditionally, data was organized in file formats. DBMS was a new concept then, and all the research was done to make it overcome the deficiencies in traditional style of data management. A modern DBMS has the following characteristics − Real-world entity − A modern DBMS is more realistic and uses real-world entities to design its architecture. It uses the behavior and attributes too. For example, a school database may use students as an entity and their age as an attribute. Relation-based tables − DBMS allows entities and relations among them to form tables. A user can understand the architecture of a database just by looking at the table names. Isolation of data and application − A database system is entirely different than its data. A database is an active entity, whereas data is said to be passive, on which the database works and organizes. DBMS also stores metadata, which is data about data, to ease its own process. Less redundancy − DBMS follows the rules of normalization, which splits a relation when any of its attributes is having redundancy in values. Normalization is a mathematically rich and scientific process that reduces data redundancy. Consistency − Consistency is a state where every relation in a database remains consistent. There exist methods and techniques, which can detect attempt of leaving database in inconsistent state. A DBMS can provide greater consistency as compared to earlier forms of data storing applications like file- processing systems. Query Language − DBMS is equipped with query language, which makes it more efficient to retrieve and manipulate data. A user can apply as many and as different filtering options as required to retrieve a set of data. Traditionally it was not possible where file-processing system was used. [Vipin Dubey] educlash.com
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
DBMS UNIT 2
OVERVIEW OF DBMS
Database is a collection of related data and data is a collection of facts and figures that can be processed
to produce information.
Mostly data represents recordable facts. Data aids in producing information, which is based on facts. For
example, if we have data about marks obtained by all students, we can then conclude about toppers and
average marks.
A database management system stores data in such a way that it becomes easier to retrieve,
manipulate, and produce information.
Characteristics
Traditionally, data was organized in file formats. DBMS was a new concept then, and all the research
was done to make it overcome the deficiencies in traditional style of data management. A modern
DBMS has the following characteristics −
Real-world entity − A modern DBMS is more realistic and uses real-world entities to design its
architecture. It uses the behavior and attributes too. For example, a school database may use students
as an entity and their age as an attribute.
Relation-based tables − DBMS allows entities and relations among them to form tables. A user can
understand the architecture of a database just by looking at the table names.
Isolation of data and application − A database system is entirely different than its data. A database is an
active entity, whereas data is said to be passive, on which the database works and organizes. DBMS also
stores metadata, which is data about data, to ease its own process.
Less redundancy − DBMS follows the rules of normalization, which splits a relation when any of its
attributes is having redundancy in values. Normalization is a mathematically rich and scientific process
that reduces data redundancy.
Consistency − Consistency is a state where every relation in a database remains consistent. There exist
methods and techniques, which can detect attempt of leaving database in inconsistent state. A DBMS
can provide greater consistency as compared to earlier forms of data storing applications like file-
processing systems.
Query Language − DBMS is equipped with query language, which makes it more efficient to retrieve and
manipulate data. A user can apply as many and as different filtering options as required to retrieve a set
of data. Traditionally it was not possible where file-processing system was used.